Download or read book Modelling Degradation of Medical Implants Made of Biodegradable Polymers written by Xinpu Chen and published by . This book was released on 2017 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Modelling Degradation of Bioresorbable Polymeric Medical Devices written by J Pan and published by Elsevier. This book was released on 2014-10-24 with total page 271 pages. Available in PDF, EPUB and Kindle. Book excerpt: The use of bioresorbable polymers in stents, fixation devices and tissue engineering is revolutionising medicine. Both industry and academic researchers are interested in using computer modelling to replace some experiments which are costly and time consuming. This book provides readers with a comprehensive review of modelling polymers and polymeric medical devices as an alternative to practical experiments. Chapters in part one provide readers with an overview of the fundamentals of biodegradation. Part two looks at a wide range of degradation theories for bioresorbable polymers and devices. The final set of chapters look at advances in modelling biodegradation of bioresorbable polymers. This book is an essential guide to those concerned with replacing tests and experiments with modelling. Provides a comprehensive mathematical framework for computer modelling of polymers and polymeric medical devices that can significantly reduce the number of experiments needed Reviews the fundamental methods of modelling degradation, and applies these to particular materials including amorphous bioresorbable polyesters, semicrystalline biodegradable polyesters, and composite materials made of biodegradable polyesters and triclcium phosphates

Download or read book Degradation of Implant Materials written by Noam Eliaz and published by Springer Science & Business Media. This book was released on 2012-08-21 with total page 521 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book reviews the current understanding of the mechanical, chemical and biological processes that are responsible for the degradation of a variety of implant materials. All 18 chapters will be written by internationally renowned experts to address both fundamental and practical aspects of research into the field. Different failure mechanisms such as corrosion, fatigue, and wear will be reviewed, together with experimental techniques for monitoring them, either in vitro or in vivo. Procedures for implant retrieval and analysis will be presented. A variety of biomaterials (stainless steels, titanium and its alloys, nitinol, magnesium alloys, polyethylene, biodegradable polymers, silicone gel, hydrogels, calcium phosphates) and medical devices (orthopedic and dental implants, stents, heart valves, breast implants) will be analyzed in detail. The book will serve as a broad reference source for graduate students and researchers studying biomedicine, corrosion, surface science, and electrochemistry.

Download or read book Novel Application of Finite Element Technique to Simulate In vitro Deterioration and Estimation of Fracture Toughness of Biodegradable Polymer written by and published by . This book was released on 2017 with total page 240 pages. Available in PDF, EPUB and Kindle. Book excerpt: Material is the most important factor in today's technological advancements. New materials are discovered and invented to help facilitate the advancement and hence in the betterment of the mankind. Material properties and its behavior, therefore, is very important in designing and manufacturing a certain part or a system. Polymer is the key material in many implantable medical devices. It is easily available. It gives a structural stability, electrical insulation and biocompatibility. The stability and functional integrity during intended and desired use is very important while at the same time, the opposite, degradation and disappearance of the polymer is also required. Poly lactide-co-glycolide (PLGA 85:15) is a polymer which has been used quite intensively in medical science as fixation devices. Their growing usage inside the human body have always been a tough challenge for orthopedic doctors and material scientists to understand the behavior of the polymer, that is, its physical, chemical and mechanical properties. This significant jump in the usage is due to the fact that they are easily available and manufactured, help in quick healing etc. However, there are instances where the recipients of the implant, made from such biodegradable polymers suddenly complained about excruciating pain during recovery period. Upon diagnostic checkup, it was revealed that the implant had cracked. Biodegradable polymers such as PLGA 50:50, PLGA 85:15 etc undergo degradation due to physiological processes inside the human body while the fractured bone, subjected to kinesiological stresses, is being healed. To avoid any complication due to premature fracture of the implant, a prior knowledge of its behavior should be known to orthopedic doctors. As per the surveyed literature, so far research studies have been conducted on physical and chemical aspects of the degradation. No study has ever been conducted on the mechanical aspect of the degradation. In order to understand how such biodegradable polymers lose mechanical strength during its intended use, an investigation into the influence of degradation process on Mode-I fracture toughness of Poly (lactide-co-glycolide) 85:15, material was initiated. The objective of this study was to build an improved understanding of the deterioration of this biodegradable polymer's mechanical properties during in-vitro degradation and how this change may affect long term performance of the implants made from such biodegradable polymers. A simple mathematical relationship was established for Mode-I fracture to understand change in the Young's modulus of PlGA 85:15 during the degradation process. Compact tension specimens were designed and molded for Mode-I fracture criterion and then put in 3% concentrated H2O2 to simulate the change in the internal structure of the polymer and how that change is affecting its mechanical properties. Fracture toughness, a key mechanical property which resist fracture as it deteriorates was the main component of this study. Extended Finite Element Method (xFEM), an extension of Finite Element Method (FEM) technique was used in this study. It is a numerical method, developed based on Linear Elastic Fracture Mechanics (LEFM) to study fracture at each stage of the degradation. xFEM models were built and analyzed at each stage of degradation. The result from xFEM analysis was then compared against the physical test result. This study inferred that with the help of physical test and xFEM analysis, biodegradable polymer, PLGA 85:15 became extremely brittle and porous as degradation progressed and hence, the fracture toughness decreased.

Download or read book Biodegradation written by Rolando Chamy and published by BoD – Books on Demand. This book was released on 2013-06-14 with total page 382 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book contains a collection of different biodegradation research activities where biological processes take place. The book has two main sections: A) Polymers and Surfactants Biodegradation and B) Biodegradation: Microbial Behaviour.

Download or read book Biodegradable Polyesters written by Stoyko Fakirov and published by John Wiley & Sons. This book was released on 2015-04-06 with total page 370 pages. Available in PDF, EPUB and Kindle. Book excerpt: Collating otherwise hard-to-get and recently acquired knowledge in one work, this is a comprehensive reference on the synthesis, properties, characterization, and applications of this eco-friendly class of plastics. A group of internationally renowned researchers offer their first-hand experience and knowledge, dealing exclusively with those biodegradable polyesters that have become increasingly important over the past two decades due to environmental concerns on the one hand and newly-devised applications in the biomedical field on the other. The result is an unparalleled overview for the industrial chemist and materials scientist, as well as for developers and researchers in industry and academia alike.

Download or read book Biodegradable Systems in Tissue Engineering and Regenerative Medicine written by Rui L. Reis and published by CRC Press. This book was released on 2004-11-29 with total page 590 pages. Available in PDF, EPUB and Kindle. Book excerpt: Conventional materials technology has yielded clear improvements in regenerative medicine. Ideally, however, a replacement material should mimic the living tissue mechanically, chemically, biologically and functionally. The use of tissue-engineered products based on novel biodegradable polymeric systems will lead to dramatic improvements in health

Download or read book Degradation of Implant Materials written by Noam Eliaz and published by Springer. This book was released on 2012-08-21 with total page 516 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book reviews the current understanding of the mechanical, chemical and biological processes that are responsible for the degradation of a variety of implant materials. All 18 chapters will be written by internationally renowned experts to address both fundamental and practical aspects of research into the field. Different failure mechanisms such as corrosion, fatigue, and wear will be reviewed, together with experimental techniques for monitoring them, either in vitro or in vivo. Procedures for implant retrieval and analysis will be presented. A variety of biomaterials (stainless steels, titanium and its alloys, nitinol, magnesium alloys, polyethylene, biodegradable polymers, silicone gel, hydrogels, calcium phosphates) and medical devices (orthopedic and dental implants, stents, heart valves, breast implants) will be analyzed in detail. The book will serve as a broad reference source for graduate students and researchers studying biomedicine, corrosion, surface science, and electrochemistry.

Download or read book Corrosion and Degradation of Implant Materials written by B. C. Syrett and published by ASTM International. This book was released on 1979 with total page 358 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Constitutive Modeling for Biodegradable Polymers for Application in Endovascular Stents written by João Filipe Da Silva Soares and published by . This book was released on 2008 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Percutaneous transluminal balloon angioplasty followed by drug-eluting stent implantation has been of great benefit in coronary applications, whereas in peripheral applications, success rates remain low. Analysis of healing patterns in successful deployments shows that six months after implantation the artery has reorganized itself to accommodate the increase in caliber and there is no purpose for the stent to remain, potentially provoking inflammation and foreign body reaction. Thus, a fully biodegradable polymeric stent that fulfills the mission and steps away is of great benefit. Biodegradable polymers have a widespread usage in the biomedical field, such as sutures, scaffolds and implants. Degradation refers to bond scission process that breaks polymeric chains down to oligomers and monomers. Extensive degradation leads to erosion, which is the process of mass loss from the polymer bulk. The prevailing mechanism of biodegradation of aliphatic polyesters (the main class of biodegradable polymers used in biomedical applications) is random scission by passive hydrolysis and results in molecular weight reduction and softening. In order to understand the applicability and efficacy of biodegradable polymers, a two pronged approach involving experiments and theory is necessary. A constitutive model involving degradation and its impact on mechanical properties was developed through an extension of a material which response depends on the history of the motion and on a scalar parameter reflecting the local extent of degradation and depreciates the mechanical properties. A rate equation describing the chain scission process confers characteristics of stress relaxation, creep and hysteresis to the material, arising due to the entropy-producing nature of degradation and markedly different from their viscoelastic counterparts. Several initial and boundary value problems such as inflation and extension of cylinders were solved and the impacts of the constitutive model analyzed. In vitro degradation of poly(L-lactic acid) fibers under tensile load was performed and degradation and reduction in mechanical properties was dependent on the mechanical environment. Mechanical testing of degraded fibers allowed the proper choice of constitutive model and its evolution. Analysis of real stent geometries was made possible with the constitutive model integration into finite element setting and stent deformation patterns in response to pressurization changed dramatically as degradation proceeded.

Download or read book Corrosion and Degradation of Implant Materials written by A. C. Fraker and published by ASTM International. This book was released on 1985 with total page 458 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book A Phenomenological Mathematical Modelling Framework for the Degradation of Bioresorbable Composites written by Ismael Moreno-Gomez and published by Springer. This book was released on 2019-04-05 with total page 325 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book presents a generalised computational model for the degradation of resorbable composites, using analytic expressions to represent the interwoven phenomena present during degradation. It then combines this modelling framework with a comprehensive database of quantitative degradation data mined from existing literature and from novel experiments, to provide new insights into the interrelated factors controlling degradation. Resorbable composites made of biodegradable polyesters and calcium-based ceramics have significant therapeutic potential as tissue engineering scaffolds, as temporary implants and as drug-loaded matrices for controlled release. However, their degradation is complex and the rate of resorption depends on multiple connected factors such as the shape and size of the device, polymer chemistry and molecular weight, particle phase, size, volume fraction, distribution and pH-dependent dissolution properties. Understanding and ultimately predicting the degradation of resorbable composites is of central importance if we are to fully unlock the promise of these materials.

Download or read book Biocompatibility and Performance of Medical Devices written by Jean-Pierre Boutrand and published by Woodhead Publishing. This book was released on 2019-11-21 with total page 586 pages. Available in PDF, EPUB and Kindle. Book excerpt: Biocompatibility and Performance of Medical Devices, Second Edition, provides an understanding of the biocompatibility and performance tests for ensuring that biomaterials and medical devices are safe and will perform as expected in the biological environment. Sections cover key concepts and challenges faced in relation to biocompatibility in medical devices, discuss the evaluation and characterization of biocompatibility in medical devices, describe preclinical performance studies for bone, dental and soft tissue implants, and provide information on the regulation of medical devices in the European Union, Japan and China. The book concludes with a review of histopathology principles for biocompatibility and performance studies. Presents diverse insights from experts in government, industry and academia Delivers a comprehensive overview of testing and interpreting medical device performance Expanded to include new information, including sections on managing extractables, accelerating and simplifying medical device development through screening and alternative biocompatibility methods, and quality strategies which fasten device access to market

Download or read book Polymers for Tissue Engineering written by M. Molly S. Shoichet and published by VSP. This book was released on 1998-01-01 with total page 460 pages. Available in PDF, EPUB and Kindle. Book excerpt: The articles included in this text highlight the important advances in polymer science that impact tissue engineering. The breadth of polymer science is well represented with the relevance of both polymer chemistry and morphology emphasized in terms of cell and tissue response.

Download or read book Handbook of Biodegradable Polymers written by Abraham J. Domb and published by CRC Press. This book was released on 1998-02-04 with total page 548 pages. Available in PDF, EPUB and Kindle. Book excerpt: Handbook of Biodegradable Polymers, the seventh volume in the Drug Delivery and Targeting book series, provides a source manual for synthetic procedures, properties and applications of bioerodible polymers. The authors describe widely available materials such as polyactides, collagen and gelatin, as well as polymers of emerging importance, such as the genetically-engineered and elastin-based polymers which are either proprietary or in early stages of development. Section I addresses synthetic absorbable polymers, and Section 2 profiles natural, semi-synthetic and biosynthetic polymers. Section 3 discusses the surface characterization of degradable polymers, the modeling of biodegradation and non-medical polymers. This book is ideal for researchers from academia and industry as well as chemists, pharmacists and physicians who deal with biopolymers, drug delivery and targeting, bioengineering and implantable devices.

Download or read book Biopolymer Composites in Electronics written by Kishor Kumar Sadasivuni and published by Elsevier. This book was released on 2016-09-10 with total page 546 pages. Available in PDF, EPUB and Kindle. Book excerpt: Biopolymer Composites in Electronics examines the current state-of-the-art in the electronic application based on biopolymer composites. Covering the synthesis, dispersion of fillers, characterization and fabrication of the composite materials, the book will help materials scientists and engineers address the challenges posed by the increased use of biopolymeric materials in electronic applications. The influence of preparation techniques on the generation of micro, meso, and nanoscale fillers, and the effect of filler size and dispersion on various biopolymers are discussed in detail. Applications covered include sensors, actuators, optics, fuel cells, photovoltaics, dielectrics, electromagnetic shielding, piezoelectrics, flexible displays, and microwave absorbers. In addition, characterization techniques are discussed and compared, enabling scientists and engineers to make the correct choice of technique. This book is a ‘one-stop’ reference for researchers, covering the entire state-of-the-art in biopolymer electronics. Written by a collection of expert worldwide contributors from industry, academia, government, and private research institutions, it is an outstanding reference for researchers in the field of biopolymer composites for advanced technologies. Enables researchers to keep up with the rapid development of biopolymer electronics, which offer light, flexible, and more cost-effective alternatives to conventional materials of solar cells, light-emitting diodes, and transistors Includes thorough coverage of the physics and chemistry behind biopolymer composites, helping readers to become rapidly acquainted with the fiel Provides in-depth information on the range of biopolymer applications in electronics, from printed flexible conductors and novel semiconductor components, to intelligent labels, large area displays, and solar panels

Download or read book Diffusion in Natural Porous Media written by Peter Grathwohl and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 198 pages. Available in PDF, EPUB and Kindle. Book excerpt: Diffusion in Natural Porous Media: Contaminant Transport, Sorption/Desorption and Dissolution Kinetics introduces the general principles of diffusion in the subsurface environment and discusses the implications for the fate and transport of contaminants in soils and groundwater. Emphasis is placed on sorption/desorption and the dissolution kinetics of organic contaminants, both of which are limited by the slow speed of molecular diffusion. Diffusion in Natural Porous Media: Contaminant Transport, Sorption/Desorption and Dissolution Kinetics compiles methods for calculating the diffusion coefficients of organic compounds (in aqueous solution or vapor phase) in natural porous media. The author uses analytical solutions of Fick's 2nd law and some simple numerical models to model diffusive transport under various initial and boundary conditions. A number of these models may be solved using spreadsheets. The book examines sorption/desorption rates of organic compounds in various soils and aquifer materials, and also examines the dissolution kinetics of nonaqueous phase liquids in aquifers, in both the trapped residual phase and in pools. Diffusion in Natural Porous Media: Contaminant Transport, Sorption/Desorption and Dissolution Kinetics concludes with a discussion of the impact of slow diffusion processes on soil and groundwater decontamination and the implications of these processes for groundwater risk assessment.